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In recent years, the pipe shed advanced support method has emerged as a new technique for excavating tunnels in weak surrounding rock. However, the necessity to maintain a certain inclination angle when constructing large pipe sheds unavoidably increases the excavation and lining quantities. Consequently, as the length of the pipe shed increases, construction errors also grow, resulting in larger excavations and backfilling works, thereby making it difficult to control the quality of pipe shed installations and limiting the development of the pipe shed method. Faced with the challenges presented by tunnel support construction as part of subway tunnel construction, this paper is based on the Songhuai Youyuan Station tunnel project involving Zhengzhou Metro Line 9. Field experiments were conducted, using high-torque horizontal drilling machines and pipe shed guiding technology to successfully complete the installation of a 208 m long pipe shed in a single operation (the longest in the world). Through case analysis and technological innovation, a feasible and effective drilling technology scheme was proposed. Compared with traditional methods, the key technology for installing super-long pipe sheds in a single operation reduced the construction time by 35% and construction costs by 25%, providing valuable insights for similar projects. [ABSTRACT FROM AUTHOR]

Up to five solidification pathways were revealed in solidification of undercooled Co79.3B20.7 alloy. As the undercooling prior to nucleation increases, the primary phase changes from Co3B to Co2B to Co23B6 and then to α-Co/Co3B eutectic. In the case that Co23B6 forms as primary phase, the alloy may completely solidify into Co23B6 or the primary Co23B6 phase is subsequently remelted and resolidified into α-Co/Co2B eutectic. Based on nucleation theories the phase competition was interpreted. [ABSTRACT FROM AUTHOR]

Buffeting performance is growing sensitive to external and internal factors with increasing span of bridge. Aerodynamic admittance is an essential parameter in analyzing buffeting performance. In this paper, aerodynamic admittance in different conditions were conducted in wind tunnel tests by section model. Three kinds of aerodynamic admittance functions were used to calculating buffeting performance respectively. It is found that the aerodynamic admittance of streamlined deck is closely related to wind attack angle, and has a small difference at different wind speeds. However, the influence of aerodynamic admittance on buffeting performance is affected by the wind speed significantly. Under given conditions, adopting the Sears function as the admittance function of a similar streamlined box girder is reasonable, while the buffeting performance result obtained by adopting an admittance function as 1.0 is very conservative. [ABSTRACT FROM AUTHOR]

Objective: To investigate the surgical efficacy and prognostic factors of T3NxM0 middle-low rectal cancer without neoadjuvant therapy., Methods: Clinical data of patients with middle-low rectal cancer undergoing TME surgery with T3NxM0 confirmed by postoperative pathology at Colorectal Surgery Department of Changhai Hospital from January 2008 to December 2010 were analyzed retrospectively., Inclusion Criteria: (1)no preoperative neoadjuvant chemoradiotherapy (nCRT); (2) complete preoperative evaluation, including medical history, preoperative colonoscopy or digital examination, blood tumor marker examination, and imaging examination; (3) distance between tumor lower margin and anal verge was ≤ 10 cm; (4) negative circumferential resection margin (CRM-). Finally, a total of 331 patients were included in this study. According to the number of metastatic lymph node confirmed by postoperative pathology, the patients were divided into N0 group without regional lymph node metastasis (190 cases) and N+ group with regional lymph node metastasis (141 cases). The perioperative conditions, local recurrence, distant metastasis and prognostic factors were analyzed., Results: Compared to N0 group in the perioperative data, N+ group had higher ratio of tumor deposit [29.8%(42/141) vs. 0, χ²=64.821, P<0.001] and vascular invasion [7.1%(10/141) vs. 0.5%(1/190),χ²=10.860, P<0.001]. There were no significant differences in tumor diameter, number of lymph nodes detected, positive nerve invasion, degree of tumor differentiation, morbidity of postoperative complication and postoperative adjuvant chemotherapy rate between the two groups (all P>0.05). The median follow-up period was 73.4 months. The merged 5-year local recurrence rate was 2.7%(9/331), 5-year distant metastasis rate was 23.3% (77/331), 5-year disease-free survival (DFS) rate was 73.4%, and 5-year overall survival (OS) rate was 77.2%. Multivariate analysis showed that lymph node metastasis (HR=3.120, 95%CI: 1.918 to 5.075, P<0.001), nerve invasion (HR=0.345, 95%CI: 0.156 to 0.760, P=0.008) and vascular invasion (HR=0.428, 95%CI: 0.189 to 0.972, P=0.043) were independent risk factors for DFS in patients with T3NxM0 rectal cancer after operation. Preoperative carcinoembryonic antigen level (HR=1.858, 95%CI:1.121 to 3.079, P=0.016), lymph node metastasis (HR=3.320, 95%CI: 1.985 to 5.553, P<0.001) and nerve invasion (HR=0.339, 95%CI: 0.156 to 0.738, P=0.006) were independent risk factors for OS in patients with T3NxM0 rectal cancer after operation., Conclusions: Optimal local control rate of middle-low rectal cancer patients with T3NxM0 and CRM- can be achieved by standard TME surgery alone. For patients with preoperative elevated blood carcinoembryonic antigen level, regional lymph node metastasis, or neurovascular invasion confirmed by pathology after surgery, adjuvant chemoradiotherapy should be actively applied after surgery to improve prognosis.

Objective: To compare the clinicopathological features and prognosis between left-sided colon cancer (LC) and right-sided colon cancer (RC)., Methods: Clinicopathological and follow-up data of 2 174 colon carcinoma cases undergoing resection at Shanghai Changhai Hospital of The Second Military Medical University from January 2000 to December 2010 were retrospectively analyzed. Patients with transverse colon cancer, overlapping position, unknown location, recurrent cancer, multiple primary cancer, concomitant malignant tumors, preoperative chemotherapy, local resection, incomplete clinical data and missed follow up were excluded. Finally, a total of 1 036 patients, whose primary tumors were radically removed, were enrolled, with 563 patients in LC group (including carcinoma in cecum, ascending colon and hepatic flexure) and 473 in RC group (including carcinoma in splenic flexure, descending colon and sigmoid colon). The clinicopathological features and survival, including median overall survival, 5-year overall survival rate, tumor specific median overall survival, cancer specific 5-year overall survival rate, were compared between LC and RC groups. Tumor specific overall survival was defined as the period between operation date to the date of death caused by cancer progression. Multivariate Cox regression analysis was used to analyze the influencing factors of survival. Propensity score matching was carried out to balance the clinicopathological factors between the two groups with the SAS 9.3, taking the following parameters into consideration (age, gender, gross appearance, tumor diameter, invasion depth, lymph node metastasis, distant metastasis, TNM stages, differentiation, CEA and CA199-9). Patients in RC group and LC group were matched according to the propensity scores and the clinicopathological characteristics and prognosis of two groups were compared again., Results: No significant differences were identified between the two groups in age, distant metastasis and serum CEA level. Compared with RC group, LC group had more male patients [60.9%(343/563) vs. 51.0%(241/473), P=0.001], more ulcerative tumors [71.9% (405/563) vs. 65.3%(309/473), P=0.006], better differentiation [well/moderately differentiated: 87.5%(493/563) vs. 73.8%(349/473), P=0.000], lower infiltration depth [T1-2: 17.1%(96/563) vs. 10.1%(48/473), P=0.001], higher lymph node metastasis rate [N0: 53.3%(300/563) vs. 62.4%(295/473), P=0.013], lower TNM stage [stage I(: 13.3%(75/563) vs. 7.8%(37/473), P=0.000], lower serum CA199 level [<37 kU/L: 68.4% (385/563) vs. 62.6% (296/473), P=0.022] and smaller tumor diameter [<5.0 cm: 55.1%(310/563) vs. 38.3%(181/473), P=0.000]. The median overall survival was 82 months and 76 months in LC and RC groups, respectively, and the 5-year overall survival rate was 58.3% and 50.9%(P=0.038). The median tumor specific survival was 84 months and 78 months in LC and RC groups, respectively, and the 5-year tumor specific overall survival rate was 60.6% and 52.9% (P=0.031). Multivariate Cox regression analysis showed that tumor location (LC vs. RC) was not associated with overall survival (P=0.106) and tumor specific survival (P=0.091). After propensity score matching, no significant difference was found in clinicopathological factors and propensity score (0.458±0.129 vs. 0.459±0.129, P=0.622) between LC and RC group. After matching, there was no significant difference in overall survival rate (54.0% vs. 51.7%, P=0.982) and tumor specific overall survival rate(56.4% vs. 53.1%, P=0.819) between two groups., Conclusion: Significant difference exists between RC and LC in clinicopathological factors, but not in survival.